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    <div class="refentry" id="gl_BoundingBox">
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      <div class="refnamediv">
        <h2>Name</h2>
        <p>gl_BoundingBox — contains the bounding box primitives generated from the output patch</p>
      </div>
      <div class="refsynopsisdiv">
        <h2>Declaration</h2>
        <code class="fieldsynopsis"><span class="modifier">patch out mediump </span><span class="type">vec4 </span><span class="varname">gl_BoundingBox[2] </span>;</code>
      </div>
      <div class="refsect1" id="description">
        <h2>Description</h2>
        <p>
            <code class="varname">gl_BoundingBox[]</code> is an array of two vec4 values that should be used instead of the value of
            <code class="constant">GL_PRIMITIVE_BOUNDING_BOX</code> as the primitive bounding box (see 
            <a class="citerefentry" href="glPrimitiveBoundingBox.xhtml"><span class="citerefentry"><span class="refentrytitle">glPrimitiveBoundingBox</span></span></a>) for primitives generated 
            from the output patch. <code class="varname">gl_BoundingBox[]</code> is
            consumed by the tessellation primitive generator, and is not available as an
            input to the tessellation evaluation shader.
        </p>
      </div>
      <div class="refsect1" id="notes">
        <h2>Notes</h2>
        <p>
            If tessellation is active, each invocation of the tessellation control
            shader may re-specify the bounding box by writing to the built-in
            <code class="varname">gl_BoundingBox[]</code> variable. If the shader statically assigns a value to
            any part of this variable, then <code class="varname">gl_BoundingBox[]</code> is used instead of
            the parameters to <code class="function">glPrimitiveBoundingBox</code>.
            If the shader contains a static assignment
            to <code class="varname">gl_BoundingBox[]</code> and there is an execution path through the shader
            that does not write all components of <code class="varname">gl_BoundingBox[]</code>, the value of
            unwritten components and corresponding bounding box coordinates is undefined
            for executions of the shader that take that path.
        </p>
        <p>
            If the tessellation control shader re-specifies the bounding box, the re-specified 
            value is used for primitives generated from the output patch by
            the primitive generator, any primitives emitted by the geometry shader
            invocations for those generated primitives, and any primitives further
            introduced during clipping.
        </p>
      </div>
      <div class="refsect1" id="versions">
        <h2>Version Support</h2>
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                <th style="text-align: center; border-bottom: 2px solid ; " colspan="4">
                <span class="bold"><strong>OpenGL ES Shading Language Version</strong></span>
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              </tr>
              <tr>
                <th style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>Variable Name</strong></span>
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                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>1.00</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>3.00</strong></span>
            </th>
                <th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
                <span class="bold"><strong>3.10</strong></span>
            </th>
                <th style="text-align: center; border-bottom: 2px solid ; ">
                <span class="bold"><strong>3.20</strong></span>
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            </thead>
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                <td style="text-align: left; border-right: 2px solid ; ">gl_BoundingBox[]</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; border-right: 2px solid ; ">-</td>
                <td style="text-align: center; ">✔</td>
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        </div>
      </div>
      <div class="refsect1" id="seealso">
        <h2>See Also</h2>
        <p>
            <a class="citerefentry" href="glPrimitiveBoundingBox.xhtml"><span class="citerefentry"><span class="refentrytitle">glPrimitiveBoundingBox</span></span></a>
        </p>
      </div>
      <div class="refsect1" id="Copyright">
        <h2>Copyright</h2>
        <p>
            Copyright <span class="trademark"/>© 2015 Khronos Group.
            This material may be distributed subject to the terms and conditions set forth in
            the Open Publication License, v 1.0, 8 June 1999.
            <a class="link" href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
        </p>
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